New Tickets not recording "Requestor"

Using RT 3.6.6 on a Cent5 base. When I, or any user, create a new
ticket, the “requestor” field is not being set to anything, the field
remains blank. Any ideas what might be happening, or where to look to
fix this?

Dan Lee
Systems Technician
LaGrange School District 102
leeda@dist102.k12.il.us